How Real Morse Code Is Sent, and How to Do It in Your Browser
Every professional telegrapher used the same basic tool: a key that made contact when pressed and broke contact when released. The timing of those presses is the code.
01One Unit. Everything Else Is a Multiple of It.
The International Telecommunication Union defines Morse timing around one base unit: the duration of a dot. A slow operator and a fast operator produce the same code shape at different tempos.
A short press. The base unit for all Morse timing.
A long press, held three times as long as a dot.
The silence between dots and dashes inside one letter.
The silence between two letters in the same word.
The longest defined pause, used between words.
One standard word equals 50 timing units.
02What HI Looks Like as a Signal
The diagram below shows H and I as a receiver would see them. High means key pressed. Low means key released. The longer low section is the letter gap.
03Your Mouse Replicates a Telegraph Key
Press and hold for a short moment to send a dot. Hold longer to send a dash. After release, pauses automatically create letter and word boundaries.
04Full A-Z and 0-9 in Timing Notation
Each cell shows the character and its dot-dash pattern. Click a cell to load its pattern into the keyer.
05Frequently Asked Questions
What is dit dah in Morse code?
Dit and dah are the spoken names for dot and dash. Dit is short and clipped. Dah is longer and held. Operators still use these words when training by sound.
How does a keyer know the difference between a dot and a dash?
It measures how long the key is pressed. A short press becomes a dot. A longer press becomes a dash. The threshold scales with the selected WPM speed.
What is the dot dash timing standard?
The ITU standard defines dot as 1 unit, dash as 3 units, intra-character gap as 1 unit, letter gap as 3 units, and word gap as 7 units.
Can I send Morse code with mouse clicks online?
Yes. The keyer on this page uses press duration and pauses to simulate a straight telegraph key in the browser.
What is the difference between a straight key and an iambic keyer?
A straight key is a single contact controlled fully by the operator. An iambic keyer uses paddles to generate repeating dots and dashes automatically.
Timing rules follow ITU-R M.1677-1. All thresholds in the live keyer scale linearly with the selected WPM setting.